:root{
  --ink:#14213d;--muted:#6b7280;--paper:#f5f7fb;--panel:#ffffff;
  --line:#dfe5ee;--accent:#0f766e;--accent2:#115e59;--danger:#b42318;
  --shadow:0 20px 50px rgba(20,33,61,.08);--radius:18px;
}
*{box-sizing:border-box} body{margin:0;font-family:"Trebuchet MS","Segoe UI",sans-serif;background:var(--paper);color:var(--ink)}
button,input,select,textarea{font:inherit} button{cursor:pointer}
.hidden{display:none!important}.center-shell{min-height:100vh;display:grid;place-items:center;padding:24px;background:
radial-gradient(circle at 15% 20%,rgba(15,118,110,.12),transparent 35%),
linear-gradient(135deg,#eef4f7,#f8fafc)}
.login-card{width:min(430px,100%);background:var(--panel);border:1px solid var(--line);border-radius:28px;padding:36px;box-shadow:var(--shadow)}
.brand-mark{width:54px;height:54px;border-radius:16px;display:grid;place-items:center;background:var(--accent);color:white;font-weight:800;font-size:25px}
.brand-mark.small{width:38px;height:38px;border-radius:12px;font-size:18px}
h1,h2,h3{margin:.2em 0}.login-card p,.muted{color:var(--muted)}
.stack{display:grid;gap:14px;margin-top:26px} label{display:grid;gap:7px;font-weight:700;font-size:14px}
input,select,textarea{width:100%;border:1px solid var(--line);background:#fff;border-radius:12px;padding:12px 13px;color:var(--ink);outline:none}
input:focus,select:focus,textarea:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(15,118,110,.1)}
.primary,.ghost{border:0;border-radius:12px;padding:12px 16px;font-weight:800}.primary{background:var(--accent);color:#fff}.primary:hover{background:var(--accent2)}
.ghost{background:#edf1f6;color:var(--ink)}.danger{color:var(--danger)}
.message{margin-top:14px;font-size:14px}.message.error{color:var(--danger)}.message.ok{color:var(--accent)}
.app-shell{min-height:100vh;display:grid;grid-template-columns:260px 1fr}.sidebar{background:#102a43;color:#f8fafc;padding:22px;display:flex;flex-direction:column;gap:18px}
.brand-row{display:flex;gap:10px;align-items:center}.brand-row span{display:block;font-size:12px;opacity:.68}.user-chip{padding:14px;border:1px solid rgba(255,255,255,.15);border-radius:14px;background:rgba(255,255,255,.05)}
.user-chip span{display:block;font-size:12px;opacity:.7;margin-top:3px}nav{display:grid;gap:6px;flex:1}
nav button{border:0;border-radius:10px;padding:11px 12px;text-align:left;background:transparent;color:#dbe7f0;font-weight:700}
nav button:hover,nav button.active{background:rgba(255,255,255,.12);color:white}.sidebar .ghost{background:rgba(255,255,255,.08);color:#fff}
.main{padding:28px 34px}.topbar{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-bottom:24px}.eyebrow{text-transform:uppercase;letter-spacing:.14em;font-size:11px;font-weight:800;color:var(--accent);margin:0}
.badge{background:#dff7f2;color:#0f766e;border-radius:999px;padding:6px 10px;font-size:12px;font-weight:800}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:0 8px 24px rgba(20,33,61,.04)}
.stat strong{font-size:32px;display:block}.stat span{color:var(--muted);font-size:13px}.toolbar{display:flex;gap:10px;align-items:end;flex-wrap:wrap}.toolbar .grow{flex:1;min-width:220px}
.results{display:grid;gap:12px;margin-top:16px}.student-card{display:grid;grid-template-columns:1fr auto;gap:18px;align-items:start}.student-meta{color:var(--muted);font-size:13px;display:flex;gap:10px;flex-wrap:wrap;margin-top:6px}
.actions{display:flex;gap:8px;flex-wrap:wrap}.actions a,.small-btn{display:inline-block;text-decoration:none;border:1px solid var(--line);background:#f8fafc;color:var(--ink);border-radius:10px;padding:8px 10px;font-size:12px;font-weight:800}
.section-title{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}.form-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.form-grid .full{grid-column:1/-1}
.table-wrap{overflow:auto}.simple-table{width:100%;border-collapse:collapse;font-size:13px}.simple-table th,.simple-table td{padding:10px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
.notice{border-left:4px solid var(--accent);background:#eefaf7;padding:12px 14px;border-radius:10px;margin-bottom:14px}.warning{border-left-color:#d97706;background:#fff7ed}
@media(max-width:900px){.app-shell{grid-template-columns:1fr}.sidebar{position:static}.main{padding:20px}.grid{grid-template-columns:1fr}.form-grid{grid-template-columns:1fr}.form-grid .full{grid-column:auto}.student-card{grid-template-columns:1fr}}